Brookfield DV-I Viscometer - Manual (Page 15)

Brookfield Engineering Laboratories, Inc. Page 15 Manual No. M/92-021-O604
II.8 Operation
The following procedure is outlined for making a viscosity measurement in a 600 ml low form
Griffin beaker.
1. Mount the guardleg on the DV-I+ Viscometer (LV and RV series). Attach the spindle to
the lower shaft. Lift the shaft slightly, holding it firmly with one hand while screwing the
spindle on with the other (note left-hand thread). Avoid putting side thrust on the shaft.
2. Insert and center spindle in the test material until the fluid's level is at the immersion groove
in the spindle's shaft. With a disc-type spindle, it is sometimes necessary to tilt the spindle
slightly while immersing to avoid trapping air bubbles on its surface. (You may find it more
convenient to immerse the spindle in this fashion before attaching it to the Viscometer.)
3. To make a viscosity measurement, select the desired speed setting. Allow time for the
indicated reading to stabilize. The time required for stabilization will depend on the speed
at which the Viscometer is running and the characteristics of the sample fluid. For
maximum accuracy, readings below 10% should be avoided. Additional information on
making viscosity measurements is available in Appendix C or the Brookfield publication
“More Solutions to Sticky Problems”.
4. Press the MOTOR ON/OFF key to turn the motor “OFF” when changing a spindle or
changing samples. Remove spindle before cleaning. Clean spindles after use.
5. Interpretation of results and the instrument's use with non-Newtonian and thixotropic
materials is discussed in the booklet, “More Solutions to Sticky Problems”, and in
Appendix C, Variables in Viscosity Measurements.
II.9 Timed Modes for Viscosity Measurement (available in instruments with V3.0 or greater)
The Timed Modes allow the viscometer user to implement Timed Stop and Time to Torque
capabilities with the DV-I+ Viscometer. This feature will allow the user to set up the viscometer
(i.e. select spindle and speed) and then record readings for a fixed period of time (Timed Stop) or
until a set torque value is attained (Time to Torque). A series of menus will ask the user to input
minutes and seconds (Timed Stop) or % torque (Time to Torque) and will then begin timing when
the user presses the
MOTOR ON/OFF key to ON. A message will be displayed showing time
remaining (or time elapsed) and the appropriate display item (viscosity or torque) will be updated
continuously during the event. Upon completion, the viscometer will display a screen stating that
the test is complete and will also display the final recorded value for the viscosity in the first case,
and the time in minutes and seconds to reach the torque limit in the second case. Pressing the
UP
or DOWN arrow keys will allow alternate data to be examined and pressing any other key will
bring the user back to the default (normal) viscometer display with the motor OFF. If the user
wishes to run another test, repeat the above steps.
II.9.1 Set Up
1. The user must pre-select the display unit option: CGS or SI.
2. The user then selects (via the UP and DOWN arrows) the spindle speed.
NOTE: If 0.0 RPM is the selected speed setting (the default after executing AUTOZERO)
the timed modes can be executed; however, the results will be meaningless
showing no viscosity values.